In medication management, compliance i.e. the degree to which a patient follows medical instructions and protocols, is often of extreme importance. In relation to injection of medicaments, one key aspect of determining the compliance is determination of the actual dose of the medication injected. Accordingly, it is desirable to provide medication delivery systems with dose quantity identification systems.
One such system is known from WO 02/092153, which discloses a medication injector apparatus, which encompasses a doseable quantity identifier for an injector pen vvhich uses a sensor to read a matrix to determine how a dose setting mechanism has been rotationally arranged by a user in setting the pen for dose administration. The apparatus further comprises an assembly for selectively rotating a drive sleeve, which assembly has a dial that rotates out during dose setting and which translates without rotation during dose injecting.
Further dose quantity identification systems may be seen in WO 03/103753, WO 2004/030717, WO 90/09202, WO 03/009461 and WO 02/064196.
It is an object of a preferred embodiment of the present invention to provide a medication delivery system, which rather than outputting the dose which is assumed to be ejected, outputs the dose which in fact was ejected.